The I/O submission and completion pathes call into the device handler without any synchronization agains detachment. So disallow detaching device handlers at runtime. Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Reviewed-by: Hannes Reinecke <hare@xxxxxxx> --- drivers/scsi/scsi_dh.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/scsi_dh.c b/drivers/scsi/scsi_dh.c index 8cae1c9..336dc54 100644 --- a/drivers/scsi/scsi_dh.c +++ b/drivers/scsi/scsi_dh.c @@ -179,8 +179,9 @@ store_dh_state(struct device *dev, struct device_attribute *attr, /* * Detach from a device handler */ - scsi_dh_handler_detach(sdev); - err = 0; + sdev_printk(KERN_WARNING, sdev, + "can't detach handler %s.\n", buf); + err = -EINVAL; } else if (!strncmp(buf, "activate", 8)) { /* * Activate a device handler -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html